1. Field of the Invention
The present invention relates to a vibration proof suspension type vibrating roller and more particularly to improvement of or relating to a vibrating roller including a rolling roller adapted to roll on the surface of a road such as a paved road or the like.
2. Description of the Prior Art
Requirements for a self-propelled vibrating roller of the above-mentioned type operation on a road surface so that vibratory energy, generated by an eccentric mass, is effectively transmitted to the road surace via the roller, and almost all transmission of vibration to the operator is inhibited. To meet these requirements, the conventional vibrating roller is provided with a plurality of vibration proof (substantially reducing vibration) members in a suspension section with the roller rotatably supported in a frame structure.
However, in a conventional vibrating roller (which includes a vibration proof suspension mechanism(, the vibration generated by the eccentric mass and a spring load are simultaneously transmitted to vibration proof members. For this reason the vibration proof members are required to have high fatigue strength to resist both vibration and spring load forces. In practice, fatigue due to vibration of the roller is negligibly small compared with fatigue due to spring load. Therefore, only fatigue due to spring load is normally taken into consideration.
Because a hydraulic motor for rotating the roller is secured to an axle plate or similar member inside the frame structure of the roller, the vibration proof members are usually fixed to a partition plate in the roller. A coupling means is connected to the output shaft of the hydraulic motor via a support plate, which is between the vibration proof members and the partition plate. Thus, as the roller is rotated by the hydraulic motor, the vibration proof members are also rotated. This rotation causes a spring load to be placed on the vibration proof members opposite in direction to the compression of the spring. Thus, the spring load acts as an alternating load during operation of the roller creating a problem of greatly increasing the fatigue of the vibration proof members.
To solve the foregoing problem, one design was to arrange a number of vibration proof members along a circular track on the partition plate in the roller. This design was intended to distribute the spring load acting on the vibration proof members. However this design causes the roller to be too large and unavoidably complicated in structure. Further, because of required increased fatigue strength and inhibition of vibration due to increased vibratory force the vibrating roller becomes greatly complicated, resulting in the vibration proof suspension mechanism being designed and constructed in disproportionately larger dimensions compared with the whole vibrating roller. Thus, the requirement for designing and constructing of a vibrating roller in smaller dimensions fails to be satisfactorily met by prior designs.
The present invention has been made to substantially overcome the foregoing problems.